SummaryThe Computing for Clean Water team has discovered how water can pass through tiny carbon nanotubes much more easily than previously predicted. This groundbreaking understanding of a fundamental physical process holds potential for improving access to clean water for millions through more efficient water filtration and desalination, as well as possible applications in clean energy and medicine. This discovery has been published in Nature Nanotechnology, the world's most prestigious nanotechnology journal.

Our team has discovered a phenomenon which forms an important step forward on the path to making clean water available to those who need it most. Clean water is fundamental to life, and yet nearly a billion people worldwide lack access to it. This isn't just a matter of convenience: over a million people die every year from diseases caused by unclean water. With population growth and climate change, the problem is expected to get worse. Existing water filter technologies are often expensive, and the people who need them most are least able to afford them. The Computing for Clean Water research that you powered can help change that status quo. These exciting findings were just published in Nature Nanotechnology, the world's most prestigious nanotechnology journal.

Fundamentally, our discovery is about how we can potentially use carbon nanotubes to make water filters that are more efficient and less expensive. Carbon nanotubes are made of single-atom-thick sheets of carbon atoms, called graphene, rolled up into tiny tubes, with diameters of just a few nanometers - one ten-thousandth the diameter of a human hair. The size of the tubes allows water molecules to pass through, but blocks larger pathogens and contaminants, purifying the water. They are so small that the scientific community initially expected that water would move through them too slowly to be useful. However, earlier experiments showed that water sometimes passes through them much more easily than expected.

Representation of volunteers contributing to the study of water within carbon nanotubes

Increased flow could mean a more efficient filter, but due to lack of sufficient computing power, until now there had been a wide gap between what scientists could understand from computer simulations, and what they could actually measure in experiments. Our research efforts focused on bridging this gap. By running massive computer simulations on World Community Grid with your help, we discovered that certain kinds of natural vibrations called phonons, under specific conditions, can lead to a 300%+ increased rate of diffusion (a kind of flow) of water through carbon nanotubes, compared to previous theoretical predictions. Importantly, since these tiny vibrations occur naturally due to thermal (heat) energy inherently stored in all materials, no external energy source is required to take advantage of this phenomenon.

What does this discovery mean for future research? The immediate application is in using the new insights from our simulations to design more efficient water filters. If experiments confirm our predictions, such filters could help improve access to clean water for millions of people worldwide. Our predictions may also lead to a less expensive method for desalinating water (the process of obtaining fresh water from sea water).

Utilizing this nanoscale phenomenon, it may be possible to construct membranes and filters that can revolutionize many processes and industries that involve water or other fluids. For instance, this discovery may reveal insights on how chemicals and medicines are transported through tiny channels in the walls of living cells. With further research, it might also be possible to apply these findings to improve a process that creates clean energy when freshwater and saltwater are mixed, a process known as osmotic power.

These diverse possibilities are only imaginable because of your generosity: no other research group had ever had the necessary computing power to run sufficiently detailed simulations to be able to compare directly with the flow conditions in real filters. By partnering with World Community Grid and the 150,000 volunteers who participated in this project, we were able to simulate water flow at a level of detail never attempted before, which revealed a phenomenon that had not been detected in previous studies.

Members of the Computing for Clean Water team: Zhiping Xu, Ming Ma Quanshui Zheng and Francois Grey

This work was a result of a global collaboration between researchers from China, Switzerland, Israel, the United Kingdom and Australia. Thanks to your participation, we were able to accomplish in just a few years what would have taken 40,000 years of computing on a single computer. On behalf of the entire team, I want to say thank you to the 150,000 World Community Grid volunteers who helped us run this research. This breakthrough belongs to you as well.